Furnace for burning pulverized fuel



T. DONALDSON. FURNACE FOR BURNING PULVERIZ'E D FUEL.

APPLICATION FlLED MAR. 18.

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Patented Apr. 4, 19iz2.v

2 SHEETS-SHEET 2- TH'ORNYCROT DONALDSGN, 0F WODLSTON. ENGLAND.

FURNC FOR BURNING 'PUJVERIZED FUEL.

Specification of Letters Patent.

Patented Apr.. 4t, 19225.

Application led March 18, 1920.. Serial No. 366,868.

T o all whom t may concern:

Be it known that THORNYCROFT DON- ALDsoN, a subject of the King of Great Britain and Ireland, residing at `Woolston, in the county of lHants, England, have invented Improvements in or Relating to Furnaces for Burning Pulverized Fuel, of which the following is a specification..

This invention relates to steam. generators adapted to be fired with pulverized fuel and it has for its object to provide an improved form of furnace and fuel introducing means.

To this end, the' invention consists in arranging that the fuel shall be directed in sheet form against an abutment in order that eddies may be produced tending to facilitate complete combustion of the fuel. Preferably a nozzle is employed which will cause the fuel to be discharged more or less in the form of a hollow cone, the: abutment being more or less annular in shape.

ln the accompanying drawings, "Fig, 1 shows partly in end elevation and partly in section on the line I-l of Fig. 2, one construction of steam generator embodying the invention, the walls and some of the Itiues necessary to provide passages for the products of combustion, being omitted. Fig. 2 is a longitudinal section of the steam generator corresponding to the line ll ll of Fig. l, also with the walls and some of the Vfines omitted. 'Fig 3 is a view to a larger scale than Figs. l and, of the fuel injecting nozzle. Fig. 4 is an end elevation correspending thereto and Fig. is a. central horizontal section. of the same. Figs. 6, 7 and 8 are sections illustrating' modifications.

Referring first to Figs. 1 to 5, a furnace a is empio 'ed having a. floor or bottom portion which is inclined forwardly towards the burner c so that any molten slag formed and resulting from the melting of the ashes from. the pulverized fuel burnt, may gravitate to the front of the furnace, or be easily removed by mechanicalmeans. il is the abutment of arcuate shape located about midway between the front and rear-ends of the furnace. is almost annularin shape but is interrupted by a gap e at the bottom, so as not to -interfere with the flow or removal of slag. The burner c comprises a pipe having a flared or conical discharge end or nozzle g into 'which is fit1 ted a conical or taperedmembcr la such as to produce an annular orifice through which the fuel is discharged, so that it issues in the form. of a hollow cone. ln order that the fuel may not bef discharged into the gap e in the abutment al, a Ldeflector or ob* structor L may be fitted in the nozzle so as to produce a corresponding gap in the conical film or layer of fuel discharged there from.

The combination of a burner such as described with an arcuate. abutment as sho-Wn, ensures a uniform combustion of fuel, thereby preventing undue admission of cold air, The furnace wall, including the floor or bottom portion b, and also the abutment d, are shown as composed of refractory material,

lf desired, the discharge orifice of the nozzle may be provided with internal guides, deflectors, `or baffles of a helical or other suitable form to control the flow of the discharged layer of fuel, one such guide being shown at j in the discharge orifice g1 between the flared pipe fland tapered member 7a2 Fig. (Land, in. some cases, the nozzle may be constructed of a pipe f2, tapered member h3 and interposed annular member f3 so as to produce passages g2 and discharge.

more than one layer of fuel as shown in Fig. 7. Also, as shown in Fig. 8, the nozzle comprising parts f", It, (/4 may beuvater j acketed to keep it cool, when necessary.

The steam generator to which such an arrangement may be applied, may be of any suitable form., it being; preferred, where one` or more such furnaces is or are incorporated Withinv a steam generator shell le having smoke tubes m above such furnace or furnaces, as in a marinetype of boiler, such as is shown in the example taken, to extend the furnace or furnaces at'fn, 'in front of the boiler, so that the fuel shall be well aflame near such vfront and the furnace at a high temperature throughout7 thereby keeping the slag fluid and capable of easy removal. ,f

1. Vln a'steam generator, a cylindrical furnace lined with refractory material., an abutment of refractory material made of arcuate shape located between the front and rear endsof said furnace, the gap between the ends of said abutment being located near to and extending to the door of said furnace anda fuel nozzle havin a flaring orifice adapted to discharge pu verized solid fuel in the form of a hacltwardly and outwardly sireadinfu hollow stream affainst said abut.-

ment.

2. In a steam generator, a cylindrical furnace lined with refractory material and having at its rear portion a forwardly and downwardly sloping bottom of refractory material, an abutment of refractory material made of arcuate shape, located between the front and rear ends of said furnace and having its ends spaced a short distance apart l to vform a narrow gap located near to and extending to the floor of said furnace and a fuel'nozzle having a tubular flaring outlet adapted to discharge pulverized solid fuel in the form of a backwardly and outwardly spreading hollow stream against said abut ment. o

3. In a steam enerator, a cylindrical furnace having a orwardly and downwardly sloping bottom, an arcuate abutment sitn ated between the front and rear ends of said furnace and subtending a large angle so that the gap between its ends is narrow and located at the lower part thereof, said gap extending to theYV floor of the furnace, a fuel nozzle having a 4flaring annular orifice adapted to discharge a hollow stream of pulverized solid fuel against said abutment and a deector in said nozzle adapted te prevent discharge of fuel into the gap in the aforesaid abutment. 4

4. In. a steam generator, a cylindrical furnace having at its forward end an extension projecting beyond the front end of the steam enerator, said furnace land extension being lined with refractory material and having a forwardly and downwardly sloping bottom also of refractory material to facilitate'the passage of molten slag over the same, an abutment of arcuate shape ar- `spreading hollow stream against said abutment.

'5. In a steam generator, a cylindrical furnace having at its forward end an extension projecting beyond the front end ofthe steam generator, said furnace and extension being lined with refractory material and having a forwardly sloping bottom to facilitate the abutment of arcuate shape. arranged between the front and rear ends of said furnace, the ends of said abutment being arranged to form a centrally disposed narrow gap adjacent to and extending to the floor of said furnace so as not to impede the passage of slag, and a pulverized solid fuel discharging nozzle terminating within the said forward extension of the furnace and having a flaring annular orifice adapted to discharge a backwardly and outwardly spreading hollow stream of pulverized solid fuel against said abutment and a deflector in said annular' orifice adapted to prevent discharge of fuel into the gap in the said abutment.

Signed at American consulate, Southhampton, England, `this twenty-sixth day of January, 1920.

THGRNYCROFT DONALDSON.

passage of moltenslag over the same, an 

